1. Field of the Invention
The present invention relates generally to systems from transmitting torque from a rotating driver to one or more items of rotating industrial equipment. In another aspect, the invention concerns a method and apparatus for starting up a large compressor driven by a gas turbine.
2. Description of the Prior Art
Rotating drivers powering rotating equipment are employed in many industrial applications. For example, facilities that produce electrical power frequently employ a gas turbine to power an electrical generator. Further, liquified natural gas (LNG) facilities typically employ at least one gas turbine or electrical motor to power a refrigerant compressor.
When large inertia and operating loads are imposed by rotating industrial equipment on rotating drivers, it may be impossible for the driver to reach operating speed while it is coupled to the rotating equipment. In the past, additional “starter” motors have frequently been employed to assist the start-up of large rotating industrial equipment. The starter motors are typically used to help bring the rotating equipment up to operating speed. However, starter motors that are powerful enough to increase the rotational speed of large rotating industrial equipment from zero to full operating speed require complex variable frequency electrical supply and control systems that are very expensive.